Arc welding



March 4 1924.

E. GRUEN FELDT `ARC WELDING Filed nb. 1s 1922 v'50 Figs. an

Patented M'ar. 4, 1924.

PATENT OFFICE.

" UNITED STATES EMIL GRUENFELDT, F CLEVELAND, OHIO, ASSIGNOB TO THE HYDRAULIC STEEL COM- PAITY, 0F CLEVELAND, OHIO, A CORPORATION OF OHIO.

ABC WELDING.

Application mearebruary 13, 1922. seriai No. 536,236.

To all whom t may concern.'

Be it known that I, EMIL GRUENFELDT, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Arc Welding,v of which the following is a' full, clear, and exact description, reference being had to the accompanying drawings. This invention relates .to joining sheet metal' parts by arc welding.

It is an-object of this invention to enable relatively thin sheet metal parts to be readily joined b arc welding, the joint to bestrong and not iaving an unsightly ridge.

A further object of this invention is to provide a backing member having guiding projections which will properly position the metal parts to be joined relativeto each. other and to the backing memberfor welding purposes. f

' Another object of this invention is to have guiding projections on the backing member so designed to permit-two metal 26' tubs to be forced together over the 'backing membeniyand over the projections to provide a with the edges of the tubs l practicalljilontact and substantiallyover the middle ofthe backing bar.

Another object ofthe invention is to roj vide an assembly for arc welding in wliich an electric current of relatively high voltage and power is used, so that it will penetrate and quickly melt to a considerable depth the substantially contacting edges of the tubs and backing bar before materially heat-, ing the metal adjacent the joint.l

n the drawings forming a /part of this specification, Figure 1 is a view parti* in section showingr a barrel with the lwe dedjoint.

ig. 2 is an enlarged section showing the joint after the tubs have been welded to the reinforcing ring. K Fig. 3 is an enlarged section showin the tubs overlying a rojection of the bac ing bar and read to welded.

Figs. 4 an 5 show plan views with dinerently shapeddprojections on the backing bar. 7 are sectional views showing modifications of the shape of the projections and their relation to the backing ring.

j In applying my invention to the joining of barrel tubs for example, a reinforcing ring 1 is sized to fit snugly in the edge portions 2A and 3 of the tubs 4 and 5. The ring 6 and these projections preferably have their greatest dimension transversely of the ring..` lThey may be made with their highest point at the center and sloping as at 7 in both die rections away from the center, so that when 1 is provided with a plurality of projections j I the tubs are forced together over these rings their edges will be deiiected outwardly at the relatively few points where the projections 6 occur on thecring.

In the form shown in Fig. 3 the projections 6 present a knife edge to thebase of the tubs which cuts into thejtub and displaces a small amount ofmetal and 4does not cause the tub to rise as much as when l these surfaces are inclined as in Figs. 6 and 7. l i

In both of these forms the ring 6' islnot attached, to either tub biit the tubs are merely pressed onto the ring axially and the projections 6 cause thevtubs to come together so that the line of contact substantially'i overlies the middle of the ring circumferentially' and is substantially in contact with the ring throughout its periphery, This assemblyi is a desirable one for arc welding, articularly when an electric current of re ativel high voltage and ampera el is available. uch a current will quick y fuse the edges of the tubs and part of the backin ring, without .injurioiisl heating any su stantial area of the meta adjacent the 'fused joint, The intense heat of the arc will besuicient to easily meltthe rojections 6 so that the backing ring and e ges will be homogeneously united and the 'ointfilled flush with the upper surface-o the sheet metal parts.

The use of an electric .current of hi h power which will quickl fuse the parts enables the operator to we d at a speed much greater than can be obtained where a lowerV powered current is used and-more electrode metal mustbe fused and de osited in the channel t`o form the joint an finish it flush with the sheet metal parts to be joined. The backing ring is made relativelyethick so that the edges of Ithe metal may fused and united with a part of the backing ring without melting thru the ring.

thoroughly i tubs so lthat they Yare best suited for the l'ilY character of electric current applied inthe Welding` operation.

The projections 6 may be either hot rolled into the strips from which the backing -rings are formed, or the strips may have recesses formed in them and pins set down in the strips, or the projections may be formed in any other suitable manner. ln case one does not desire to use a metallic electrode, a carbon electrode can be used, in which case additional metal to be fused can be added in any suitable form, such as a Wire, rod, pleces, etc.

What I claim is: f

1. A joint produced by arc welding comprising a backing bar having a. plurality of projections, a pair of sheet metal members overlying said backing bar and projections,

the edges of said sheet metal parts being secured to said bar by fusion of said edges, said projections and said bar.`

2. A joint produced by arc Welding comprising an annular backing bar having a plurality of centering projections, tubs positioned with their opposed edges in contact and overlying the backing bar and its projections, said tub edges, projections and backing bar being fused together.

3. An assembly for arc Welding comprising an annular backing bar carrying centering projections, and sheet metal tubs resting on said bar with their edges substantially in contact and overlying said bar, said projections serving to hold the tub edges substantially over the middle point of the peripheral face of the backing bar.

4. An assembly for arc welding comprising an annular backing bar having centering projections, and tubs positioned with their edges opposed and overlying said bar and projections.

5. The herein described method of joining sheet metal tubs which comprises positioning the edges of the tubs substantially over the middle or'` a backing bar, said bar having projections to frictionally hold the tubs in Vplace for Welding, and directing an arc against the opposed tub edges to fuse them lgogether and to unite them to the backing 6. The herein described method of .joining sheet metal tubs which consists in pressing them together over an annular backing bar carrying projections, said projections causing the edges of the tubs to frictionally engage the bar and come together substantially in Contact centrally of the peripheral face of said bar, and directing an arc against said edges to unite the edges, projections and bar by fusion.

7 'A barrel comprising a central reinforcing ring having a cylindrical face, a plurality of relatively low projections on said face, a pair of tubs having their edges fitting against the face of the ring and frictionally held in place by said projections, said edges, projections and bar being fused together.

In testimony whereof, I hereunto aiiix my signature.

EMIL GRUENFELDT. 

